1. Field of the Invention
The present invention relates to a multi-actuator, and more particularly, to a method of insertion-molding a spring into a case of a multi-actuator.
2. Description of the Related Art
Generally, a multi-functional actuator has functions to generate receiving signals, such as an audio signal and a vibration signal which are converted from a signal received as an electrical signal or from a pre-stored bell or melody signal, as a received call signal. Such a multi-functional actuator having the above functions has been used in a mobile telecommunication terminal, such as a wireless phone or a pager.
FIG. 1 shows a structure of a conventional multi-functional actuator. Referring to FIG. 1, the multi-actuator includes a case 108 having an inside space and a groove formed on an inside wall thereof, a vibration plate 101 having an outside portion fixedly coupled to an upper side of the case 101 to generate an audio signal, a voice coil 102 coupled to a lower-portion of the vibration plate 101, a magnet 104 vertically magnetized, an upper plate 103 mounted on the magnet 104 to form a magnet field, a yoke 105 forming the magnetic field with the magnet 104, a weight 106 forming a vibration body with the yoke 105, springs 107 and 109 fixedly coupled to grooves of the case 101, a lower grill 111 coupled to a lower side of the case 108, and a vibration coil 110 mounted on the grill 111 to generate the vibration using a magnetic force formed by the magnetic field.
The case 108 forming an exterior appearance of the multi-actuator is made of thermal plastic material, polycarbonate (PC) or polybuthyleneterephthalate (PBT) among general engineered plastic is used as the thermal plastic material.
The springs 107 and 109 are fixedly coupled to the case 108 of the multi-actuator using a method of coupling the springs 107 and 109 to the case 108 by inserting and assembling the springs 107 and 109 to an injection molding of the case 108 or another method of attaching the springs 107 and 109 to the case 108 with a bonding material.
The springs 107 and 109 can be more fixedly coupled to the case 108 suing the method of inserting the springs 107 and 109 into the case injection molding than the another method of bonding the springs 107 and 109 to the case 108, and a manufacturing process of the injection molding method is more simple than the bonding method. However, the injection molding method is disadvantage that the springs 107 and 109 can be deformed or distorted during inserting and insertion-molding the springs 107 and 109 into the case 108.
FIG. 2 is a view showing the spring 107 or 109 manufactured by the insert injection method and used in the multi-actuator shown in FIG. 1.
Generally, grooves 107a formed inside the springs 107 and 109 to be used as a guide, so as for the springs 107 and 109 to be individually inserted into the case 108 in the case injection mold.
FIG. 3 is the case and the spring inserted in the case of the multi-actuator shown in FIG. 1.
When the injection molding is injected in the in a case that the groove 107a and an inside of the spring 107 are used as the guide, and a problem occurs, that is, the height of the spring 208 with respect to the case 108 varies due to the interference with a guide pin coupled to the spring 107 which in supported by the guide pin. Accordingly, an assembling characteristic of the multi-actuator made using the above method deteriorates.